Asian Indians have high rates of diabetes, prediabetes and cardio metabolic risk factors. There is strong evidence that lifestyle change, particularly weight loss, increasing physical activity, and improving diet quality can prevent or delay diabetes, reduce cardiometabolic risk factors such as elevated glucose, plasma lipids, and blood pressure, and improve outcomes among individuals with diabetes. Implementing lifestyle change education and support at the worksite may be an effective and cost-effective method to deliver prevention in a way that is acceptable, accessible, and sustainable and overcomes barriers to lifestyle change (e.g., lack of time or resources). Building off previous work by the international study team, this study proposes implementing and evaluating in a pre-post design trial the acceptability, delivery, effectiveness, and cost- effectiveness of a worksite-based lifestyle improvement package including a peer-led lifestyle change education program augmented with changes in the worksite environment that promote social support, healthy eating and exercise. The lifestyle education program will include 2000 adults with prediabetes (HbA1c of 5.7- 6.4%) or unmedicated diabetes (HbA1c = 6.5% identified at screening) across eight diverse worksites in India (changes to the worksite environment will impact a much broader population of employees). A mixed methods approach will be used to evaluate implementation of the program. The study aims to measure: (1) Success of implementation in terms of program adoption (participation and changes in weight and diet and physical activity behaviors among lifestyle class participants); fidelity to the program (activities of study-affiliaed worksite staff; changes to the food options at the worksite canteen; management support for the program; and changes in the worksite environment); and program acceptability as reported by employees, managers, supervisors, and lifestyle education program participants and dropouts during in-depth, semi-structured interviews and focus group discussions. (2) Program effectiveness by evaluating the number of cardiometabolic risk goals reached for reductions in blood pressure, triglycerides, and HbA1c (the primary outcome) and through changes in secondary outcomes including rates of diabetes incidence and regression to normoglycemia and changes in anthropometry, lipids, and fasting glucose. (3) Value and return on the investment of the program for employers by assessing program costs, cost-effectiveness, and changes in staff productivity, absenteeism, health status, and quality of life. This project will deliver scientific innovations (lifestyle education programs with text message supports during maintenance) with social innovations (educated peer health educators delivering a program to a large at risk population) and business innovation (worksite stakeholder commitment and partnering researchers to help deliver the program with fidelity, improve the workplace health environment, and evaluate the model). If the program is shown to be feasible, acceptable, effective, and cost-effective at these worksites, the program could be disseminated to other worksites throughout India and elsewhere.